Device and method for jet propulsion through a water medium



3 Sheets-Sheet l TO FUEL TANK F. ZWICKY ETHOD FOR JET PROPULSION THROUGH A WATER MEDIUM lOc O I E DEVICE AND M June 23, 1964 Filed Nov. 19, 1948 INVENTOR. FRITZ ZW/C/(Y BY J), M, 4 ATTORNEY June 23, 1964 F. ZWICKY 3,137,994 DEVICE AND METHOD FOR JET PROPULSION THROUGH A WATER MEDIUM Filed Nov. 19, 1948 3 Sheets-Sheet 2 JNVENTOR. FRITZ ZW/C/(Y ATTORNEY June 23, 1964 F. ZWICKY 3,137,994 DEVICE AND METHOD FOR JET PROPULSION WATER MEDIUM THROUGH A Filed NOV. 19, 1948 3 Sheets-Sheet 3 57 .59 TIMER r COIL 1 VIBRAT'OH 34 i0 INVENTOR. FRI 72 ZW/CKY BY ATTORNEY United States Patent 3,137,994 DEVICE AND METHOD FOR JET PRGPULSIGN THRGUGH A WATER MEDIUM Fritz Zwi'cky, Pasadena, Calif., assignor to Aerojet- General Corporation, Cincinnati, Ohio, a corporation of (lhio Filed Nov. 19, 1948, Ser. No. 61,048 Claims. (Cl. 6035.6)

This invention relates to jet propulsion and more particularly to jet propulsion devices operable in Water.

The principal object is to provide a jet propelled device adapted to be effectively and economically propelled through water, with high eificiency.

A related object is to provide such a device capable of utilizing readily available and inexpensive fuels such as gasoline for a large part of their power.

Various forms of devices for jet propulsion through water have heretofore been proposed. In my copending application Serial No. 550,693, filed August 23, 1944, now US. Patent 2,914,913 issued December 1, 1959, I have disclosed and claimed a jet propulsion device operable through water, comprising a duct through which the water flows, and with means for injecting water-reactive chemicals into the water to produce gas under pressure for expelling the products from the rear of the duct. Other devices comprising a duct for flow of the water have been proposed in which the operation has been carried on by combustion of fuel-air mixtures in a reaction combustion chamber to give the desired impulse to the column of water in the duct.

In accordance with my present invention, I provide a device of this general character comprising a duct through which the water flows, the duct being equipped with a pressure-operable valve which regulates the fiow of water into the duct. For surface operation, or operation at shallow depths, the driving power or thrust is obtained by introducing a water-reactive fuel and a fuel-air mixture into the reaction-combustion chamber. For underwater operation at considerable depth the driving power, or thrust, is developed entirely by water reactive fuels.

Hereafter, I refer to such a device as an interfacial hydropulse. The term interfacial has been applied 'to hydrojet engines which utilize both the oxygen in the water, through which the device is travelling, and oxygen from the air which is automatically sucked into the device through suitable conduits to generate the gases under pressure required to drive the water out of the duct at high velocity. The expression interfacial indicates that the hydrojet engine operates in the interface between air and water. The chemical reactions involved in the interfacial hydropulse are:

(a) a reaction of hydrofuel and water;

(12) the gases generated by reaction (a), plus added fuel, are then combusted in freely drawn in air. The reactions ((1) and (b) may take place in quick succession in each pulse (or stroke) or the two reactions may take place in two successive pulses.

Fuels which react vigorously with water under ambient conditions, or react when the fuel is introduced into the water after heating, are hereafter referred to in this application as hydrofuels.

According to a feature of my invention, a hydrofuel is reacted in a reaction-combustion chamber which is associated with the duct in such a manner that the water from the duct may enter or leave the reaction-combustion chamber. The formation of gaseous products under pressure by the reaction of this fuel with the water in the chamber creates the energy which drives the water out of the chamber causing the gases to over-expand. The

subsequent contraction in volume then sucks into the chamber either air, or preferably a fuel-air mixture from a suitable carburetor device. My apparatus may be operated in two distinct and separate ways, namely, a twocycle operation, or a single-cycle operation.

In the two-cycle operation, hydrofuel is injected into the reaction chamber, gases under pressure are generated and expand against the water. The overexpansion of the gases in the duct creates a pressure lower than that of the surrounding medium that sucks in fuel-air mixture or fuel and oxygen through the carburetor, which in turn mixes with the hydrogen thatwas formed by the reaction of the hydrofuel and the water, and this mixture is then fired creating combustion gases under pressure. The apparatus is operated by a rapid series of these alternate reactions and the resulting pressure peaks occurring at each cycle drive the column of water and a portion of the reaction products rearwardly from the device. A slight amount of precompression of the fuel-air mixture is obtained before it is fired.

The single-cycle operation, which is the preferred form of operation, comprises mixing the fuel with air and introducing it into the reaction-combustion chamber simultaneously with the hydrofuel. The fuel may consist in part of the combustible gases that will be generated by the reaction of the water and hydrofuels. The fuels also may have dissolved therein a hydrofuel in which case both substances are introduced simultaneously into the chamber and are then mixed with the air which has been sucked into the chamber. The entire mass of reactants are fired simultaneously.

Examples of such combinations are mixtures of ordinary fuels such as gasoline, etc., in combination with aluminum borohydride dissolved in the gasoline. Other combinations that could also be used are hydrazine with lithium borohydride dissolved therein, or ammonia containing lithium borohydride dissolved therein.

The amount of work obtainable from a given volume of fuel in this form of operation is exceptionally high due to the fact that the fuel-air mixture is precompressed just prior to being exploded by the gases generated by the reaction of the hydrofuel with the water in the chamber.

A further feature is a provision of a reaction-combustion chamber having a front opening and a rear opening and, according to further refinements, the reaction-combustion chamber may be provided with a valve or directional barrier at one or both of the openings across either one or both of the ends.

As mentioned above, the ,device according to this invention will ordinarily find its greatest usefulness for operations at or near the surface of the water where a supply of air to form the fuel-air mixture, or to carburet the gases generated by the reaction of the hydrofuel and water, is readily available. The unit may be operated at greater depths if provision is made to carry the necessary oxygen or air, or in those cases where the operation depends entirely on the use of a hydrofuel alone.

A feature of the operation resides in the fact that the energy for forcing the water out of the duct through the exhaust opening is supplied by the heat of combustion of the water-reactive fuel, rather than by the heat of hydroysis. This is a considerable advantage, because the heat of combustion can be much greater than the heat of hydrolysis.

The foregoing and other features of my invention will be better understood from the following description and accompanying drawings of which:

FIG. 1 is a longitudinal cross-sectional view, partly in section, of an interfacial hydropulse according to my invention;

' of the chamber.

FIG. 2 is a cross-section view taken at line 2-2 of FIG. 1;

FIG. 3 is a cross-section view taken on the line 3--3 of FIG. 1. showing a reed-valve assembly;

FIG. 4 is a perspective view of one of the valve reeds used in the reed valve assembly of FIG. 1; 7

FIG. 5 is a perspective view of two channels of the reed valve assembly of FIG. 1;

.FIG. 6 is a cross-section View showing the manner in which a reed of the valve assembly of FIG. 1 operates;

FIG. 7 is a longitudinal view, partly in crosssection, showing a device according to my invention which is modified from the arrangement of FIG. 1;

FIG. 8 is a cross-section view taken on the line 8-8 of FIG. 7; 7

FIG. 9 is an end view looking into the forward end of the device of FIG. 7; and

FIG. 10 is a schematic view showing a timing system I for timing the firing and hydrofuel injections in the devices shown in FIGS. 1 and 7.

The jet motor shown in FIGS. 1 to 6 comprises a duct 10 having an inlet opening or mouth 11 and an exhaust opening or pipe 12. Within the inlet opening 11 there is located a valve assembly 13 and between the valve assembly 13 and the exhaust opening 12 there .is provided a reaction-combustion chamber 14. The portion of duct 10 surrounding the chamber 14 is made larger in diameter than the outside diameter of the chamber 14, so as to provide an annular passageway between the outer wall of the chamber and the inner wall of the duct. In front of the chamber. 14 theduct .has a substantially square cross-section 10a which is the largest cross-section of the drical from about the forward end of the chamber 14 to a position just forward of the exhaust opening 18 Rearwardly from this position the diameter ofthe duct gradually reduces to conform to the relatively smaller diameter of the exhaust pipe 12.

The reaction-combustion chamber 14 is held in position in section 100 of duct 10 by a plurality of longitudinally extending fins 15 which support the reaction-combustion chamber therein. The reaction-combustion chamber 14 is preferably cylindrical in shape throughout the major portion of its length, and its forward end 17 is 7 provided with a streamlined nozzle opening 19 preferably of the De Laval type having a throat 20 which is con 7 siderably smaller than the .diameter of the major portion of the reaction-combustion chamber. The exhaust opening 18 of the chamber is slightly smaller in crosssection than the principal cylindrical portion of the chamber. Opening 18 is provided with a plurality of directional barriers 21, extending across the entire face of the opening. These can be straight strips having a cross section with the bottom or rounded end of the U pointing upstream. The distance between the adjacent barriers is made small thereby forming straight slits 22 (FIG. 2) through which water or gases may pass at a slow rate. These barriers shaped this way act as a channel valve, permitting flow of fluid much more readily in the downstream direction than in the upstream direction.

A fuel induction pipe 23 is provided near the forward 4 end of the reaction-combustion chamber 14 and preferably enters the reaction-combustion chamber in an offcenter position and tangential direction as shown in FIGS. 1 and 2. The upper portion of induction pipe 23 leads from a valve housing 24 to the upper part of which there is connected the outlet from a fuel-air carburetor 25, which may be of a conventional type such as is used in internal combustion engines. 7 Valve housing 24 is provided with an internal valve seat 26 on which a poppet valve 27 seats, the valve being normally closed against its seat by action of coil compression spring 28. The lower ventional spark timing arrangement and needs no further discussion here; any suitable timer could be used, as is well-known in the art. A second conduit 34, located slightly downstream of 'theentry of induction pipe23 into the reaction-combustion chamber, supplies a hydrofuel to the motor from a source 34a. The hydrofuel should be one which is spontaneously reactive with water, and it is sprayed into the reaction-combustion chamber through a nozzle 35 at the endof the conduit 34. The timer device 30 also controls the intermittent admission of the hydrofuel from source 34a into the conduit 34. The means 58 for intermittently introducing the hydrofuel into the reaction-combustion chamber can be some suitable control device, for example,

an ordinary solenoid-operated shut-01f type of valve like that manufactured and sold under the designation C- 4074 bythe Savall Company, Los Angeles, California. The valve assembly13, locatedat the entrance of the duct, is illustrated in detail in FIGS; 3 to 6. The valve is of theflutter or blade type and is built up by assemblingflexible blades or reedsalternately between rigid channel members 41.

Each channel member 41 comprises a rectangular-plate 42, theupper surface of which is provided with a plurality of partition members 43 which are preferably integral with the plate 42 and run parallel with each 7 other. These partition members form a series of channels 44 preferably tapering in depth, being deeper at the leading edge 45 and becoming zero at the rear edge 46.

The valve unit 13 isassembled by alternately interleaving flexible blades 49 between the several channel members 41. These blades 40 are firmly held near their leading edges by exerting pressure upon the channel plates 42 .as shown in FIGS. 5 and 6. The banks of rigid channel members and reed valves are clamped together in the valve housing by a pair of bolts 48 to pass through holes 49 provided in both the flexible blades 40 in the rigid channel member 41, as shown.

FIGS. 5 and 6 show more clearly thev manner in which the valve, blade is sandwiched between two adjoining channel members. The view shown'in FIG. 6 is taken looking into the channel member when a portion of the valve blades iscut away. The arrangement'is such that the lower face 54 of the reed is able to vibrate thus alternately contacting and moving away from the upper edges 55 of partitions 43. This creates the valve action which normally places the valve in closed position, particularly whenever the pressure on the downstream side of the valve assembly exceeds the pressure acting against pressure on the upstream side of the valve bank is. greater the reeds from the upstream side and allows the valve to open permitting the flow of liquid through'it when the than the pressure onthe downstream side. In this condition the valve reeds are -pushed-away from thechannel partitions 43 permitting fluid to pass by the rear end of the channel member. V

A side of the valve assembly is placed under compresv ,sion by a series of compression bolts 50 which press against the bearing plate 51. Although valve housing 47 is shown as having a rectangular cross-section, it should i the duct.

be understood that some other desired shape might be used, dependingon circumstances such as'the'shape of When a series of these channel members and ceding the reaction-combustion chamber 14. For purpose of assembly, the valve is preferably assembled separately, and then slipped into the housing 47 where it is clamped in place by a plurality of bolts 48. A pair of shouldershaped retainers 52 which are attached to the forward portion of the side of duct opening 11 hold the valve in place.

FIGS. 7, 8 and 9 show a modification of the device of FIG. 1, the principal difference between these two devices being that the reaction-combustion chamber 14 in FIG. 7 is provided with a lightly loaded pressure-operable valve 56 at its forward end, which is arranged to remain closed during the periods of pressure in the chamber 14. Whenever the pressure in the reaction-combustion chamber drops below ambient, the valve opens, and due to its considerable cross section it permits a rapid scavenging of the reaction-combustion chamber with fresh water.

In this device the valve bank 13a, controlling the main flow of water through the duct from the main intake may be positioned surrounding the reaction-combustion chamber, as the closing of poppet valve 56 during periods of chamber pressure will serve to prevent water being ejected out the inlet opening from the chamber. The construction of this valve is generally similar to that shown in FIGS. 3 to 6, except that the central portion of the valve bank is removed to fit around the reactioncombustion chamber as shown in FIG. 8.

The term hydrofuel referred to in this application means water-reactive chemicals and the term aerofuels means fuels which are to be mixed with air or oxidizing gas to insure their combustion, such as gasoline; the term fuel-air mixture means the mixture of such an aerofuel with air.

Hydrofuels include water-reactive metals of low molecular weight such as lithium, sodium, magnesium, potassium, boron, aluminum, beryllium; alloys of the above metals such as sodium potassium alloy; light metal hydrides usch as 13 1-1 and other boron hydrides, lithium hydride, or hydrides of the above-listed metals, hydrides containing two or more of the above metals in the compound, such as lithium aluminum hydride; light metal borohydrides, such as lithium borohydrides and aluminum borohydride, also water-reactive organo-metallic compounds such as zinc diethyl, zinc dimethyl, aluminum trimethyl and aluminum triethyl.

Broadly stated, the device may be said to be powered by various combinations of the four propellant components which are supplied to the reaction-combustion chamber. These may be divided into:

(1) Water reactive chemicals (hydrofuels);

(2) Freewater;

(3) Aerofuels, such as gasoline, hydrogen or light hydrocarbons; and

(4) Free air, or oxygen.

Some of the components which would normally fall in groups 1 and 3 have the added properties that they are reactive in either air or water. For example, aluminum borohydride, or aluminum sesquihydride will react when in contact either with Water or air.

Likewise component number 1 may be the source of component number 3, for example; metal hydrides react with water to produce large quantities of hydrogen gas and organo-metallic compounds, such as aluminum trimethyl and triethyl react with water to form hydrocarbon gases such as methane or ethane. These gases may be mixed with air drawn in through the carburetor forming an explosive mixture in the reaction-combustion chamber.

To start the devices of FIGS. 1 or 9 in operation, there may be introduced a small amount of hydrofuel through conduit 34 and nozzle 35 into the reaction-combustion chamber. When this material comes in contact with the water within the reaction-combustion chamber, reaction occurs, developing gas under pressure which tends to force any liquid out of the chamber. The inertia of the water thus moving from the reaction-combustion chamber has a tendency of overexpanding the residual gas in the chamber, thereby causing a suction which places the reactioncombustion chamber and induction tube under reduced pressure, thereby opening the poppet valve against the action of its spring and permitting a carbureted mixture of gasoline and air to enter the reaction-combustion chamber from the carburetor through fuel conduit 23, and opening the blade valve assembly 13 to admit water to the duct. When the pressure in the chamber 14 rises to atmospheric and above, as a result of this action, the conduit 23, as well as a portion of the reaction-combustion chamber will contain a combustible fuel-air mixture and at this point the spark plug 29 will be fired to ignite the combustible charge in the fuel firing conduit 23 and the reaction-combustion chamber. The resulting gases and heat drive any water that is within the reaction-combustion chamber out through the directional barrier with sufiicient velocity to cause another overexpansion in the chamber. The chamber then sucks in water from the duct through the directional barrier and the front end nozzle 17, and at the same time it draws in a new fuelair mixture through the carburetor past the control valve 27. Another charge of hydrofuel is then injected, in response to the timing system 30, into the reactioncombustion chamber through conduit 34 and immediately reaction takes place when this hydrofuel strikes the water that has just been drawn in. The resulting pressure developed by the reaction places the fuel-air mixture in the induction tube under compression and after approximately miximum compression has taken place the spark plug fires this compressed fuel-air mixture. The combination of the escaping gases from the hydrofuel reaction and the combustion of the carbureted mixture raises the pressure, closing the blade valve 13, and drives the column of water which is in the outer duct surrounding the reaction-combustion chamber, out through the exhaust pipe 12.

These timed intermittent injections of the hydrofuel, and this action of alternate firing or reaction of the hydrofuel-water mixture, controlled by the timer 30, and the carbureted mixture continues at a rapid rate with attendant opening and closing of the valves, as just described, and this causes the water to continue to enter the inlet and to be expelled at the outlet along with the reaction products; thus creating the thrust for propulsion. Some of the water passing through the duct travels through the annular space between the reaction-combustion chamber and the duct; and other portions of the water are drawn into, and pushed out of, the reaction-combustion chamber as determined by the timed firing rate.

In the event it is desired to use a hydrofuel that will generate either hydrogen or hydrogen gases by reacting with the water, it would not be necessary to supply any additional fuel such as gasoline to the carburetor. In such a case, the carburetor would merely pass enough air through the valve 27 to permit the formation of a combustible mixture with the hydrogen within the reaction-combustion chamber and conduit 23. Such hydrogen-air mixture would then be exploded by the heat and pressure generated by the reaction of the hydrofuel.

Another possible manner of operation is to deliver from the carburetor such a lean fuel-air mixture that it would not normally explode, in combination with the hydrogen gas generated by the reaction of the hydrofuel with water. The addition of even small amounts of hydrogen to the air can be utilized to form a good combustible mixture. After the firing of the fuel-airmixture the cycle repeats itself, beginning with the injection of a new amount of hydrofuel into the reaction-combustion chamber to react with the water that has been sucked in by the overexpansion of the gases; followed again by the firing of the fuel-air mixture.

The poppet valve 27, whichcontrols the flow of fuelair mixture, or air into the induction pipe 23, is preferably lightly loaded with the spring 28 which normally keeps 'the valve closed. The loading, however, is' sufiiciently ture during the period when the pressure continues to be below the pressure of the surrounding air.

The presence of the directional barrier in the rear of the reaction-combustion chamber prevents the over-rapid entry of water into the reaction-combustion chamber during the period when the new charge is being drawn into the reaction-combustion chamber through valve 27. Likewise this directional barrier has a tendency of retaining'a portion of the pressure developed by the reaction of the hydrofuel with the water for a relatively long period of time, permitting the precompression of the fuel-air mixture to a higher degree before it is fired.

The devices according to my invention have many advantages over prior known jet propulsion devices for operation through water. An important advantageof my invention resides in the high thermo-dynamic efiiciency of operation which makes possible high thermo-propulsive yields. This follows from the high pressure at which the carburetor or fuel-air mixture is fired in cooperation with the heat of combustion of the hydrofuel utilized for pushv ing the water column out the duct. A particular advantage of my devices is that they can utilize effectively a relatively large proportion of the available energy of the hydrofuels named hereinafter, particularly organo-metallic compounds which react spontaneously in water to generate hydrocarbon gases. Such substances have heretofore been considered impractical to use, because the development of carbon during their reaction has heretofore been considered detrimental to the eflicient operation of the device. But in the operation of the present device in the water, the formation of carbon is not detrimental.

A further advantage resides in the possibility of using fuel-air mixtures which are normally too lean to be exploded, this being accomplished by the generation of the combustible hydrogen or hydrocarbon formed during the reaction of the water and a hydrofuel which gives the hydrogen or hydrocarbon. Such generated hydrogen or bydrocarbon can thus enrich the lean fuel-air mixture to the point Where it will readily explode. Such use of lean fuelair mixtures in combination with a high ratio of water to hydrofuel provides an operation capable of achieving great thrust augmentation.

A further advantage of the construction is that the reaction-combustion chamber is arranged to scavenge itself rapidly, thus permitting the device to develop a relatively high specific cross-sectional thrust.

I claim:

1. A jet propulsion device adapted for operation through water comprising: a duct having an inlet opening and an exhaust opening, an automatic pressure-operable inlet valve located within the duct for intermittently blocking the passage of water entering the duct from said inlet opening, means providing a reaction-combustion chamber within said duct, said reaction-combustion chamber being provided with an inlet opening and having an outlet located within the duct downstream of said auto-.

matic pressure-operable valve, a fuel mixing carburetor having an outlet conduit leading into said reaction-combustion chamber for admitting carbureted mixture therein, an automatic pressure-operable carburetor outlet valve located at said outlet conduit between said carburetor and 8 terial intermittently into the chamber and to energize the firing means intermittently between the injections of the "water-reactive material, wherebythe pressure generated by said reactions and explosions drive pistons of water intermittently downstream through said duct exhaust opening. v

2. A jet propulsion device adapted for operation through water comprising: a duct having an inlet open- -ing and an exhaust opening, an automatic pressure-operable inletvalve located within the duct for intermittently blocking the passage of water entering the duct from said inlet opening, means providing a reaction-combustion chamber within said duct, said reaction-combustion chamber being provided with a pressure-responsive poppet valve to 'permit water to enter the reaction-combustion chamber when the pressure within the reaction-combustion chamber is less than the pressure within the duct, and having an outlet located within the duct downstream of said automatic pressure-operable valve, a fuel mixing carburetor having an outlet conduit leading into said reaction-combustion chamber for admitting carbureted mixture therein, an automatic pressure-operable carbu- 'retor outlet valve located at said outlet'conduit between said carburetor and said reaction-combustion chamber,

means for introducing water-reactive material into said reaction-combustion chamber intermittently to cause a reaction between said water reactive fuel and water within said reaction-combustionv chamber thereby elevating the pressure within said firing chamber, and firing means timed to explode said carbureted mixture entering the reaction-combustion chamber through said conduit at elevated pressure, between intermittent injections of the Water-reactive material, said reaction and explosion driving a piston of water intermittently downstream through said duct exhaustopening. a

3. A jet propulsion device adapted for operation through water comprising: a duct having an inlet opening and an exhaust opening, an automatic pressure-oper able inlet valve-located within the duct for intermittently blocking the passage of water entering the duct from said inlet opening, means providing a reaction-combustion chamber within said duct, the forward end of the reactioncombus'tion' chamber being provided with an entry nozzle and having an outlet located within the duct downstream from said automaticpressure-operable valve, said automatic pressure-operable inlet valve within the duct being positioned upstream from said reaction-combustion chamber entry nozzle, afuel-mixing carburetor having an outlet conduit leading into said reaction-combustion chamber for admitting carbureted mixture therein, an automatic pressure-operable carburetor outlet valve located at means timed to explode said carbureted mixture entering the reaction-combustion chamber through said conduit at the elevated pressures, whereby the pressure of the ,reaction and explosion drives pistons of water intermittently downstream throughsaid duct exhaust opening.

4. A jet propulsion device adapted for operation through water comprising: aduct having an inlet opening and an exhaust opening, an automatic pressure-operable inlet valve located within-the duct for intermittently blocking the passage of water entering the duct from said inlet opening, means providing a reaction-combustion chamber within said duct, said reaction-combustion chamber being provided with an inlet opening and having an outlet located withinuthe duct downstream from said automatic pressure-operable valve, the rear end of the. reaction-combustion chamber being provided with a directional barrier extending substantially across the area described by said exhaust opening of the reaction-combustion chamber, a fuel-mixing carburetor having an outlet conduit leading into said reaction-combustion chamber for admitting carbureted mixture therein, an automatic pressure-operable carburetor outlet valve located at said outlet conduit between said carburetor and said reactioncombustion chamber, a conduit for introducing waterreactive material into said reaction-combustion chamber intermittently and thereby causing a reaction between said water-reactive fuel and water within said reactioncombustion chamber, thereby elevating the pressure within said reaction-combustion chamber, firing means timed to explode said carbureted mixture admitted into the reaction-combustion chamber through said conduit, whereby pistons of water are driven intermittently downstream through said duct exhaust opening.

5. A jet propulsion device according to claim 4 in which the directional barrier comprises a plurality of U- shaped members spacially arranged across the entire surface described by the exhaust opening of said reactioncombustion chamber.

6. The method of operating through water a jet propulsion device of the type comprising a duct having an inlet opening through which water enters the duct and an exhaust opening through which water leaves the duct, said method comprising intermittently causing masses of water to pass into the duct from the inlet opening, intermittently injecting into a chamber within the duct a waterreactive fuel to produce intermittent reactions with the Water in said chamber, and intermittently firing in the chamber a carbureted fuel-air mixture, the firings of the fuel-air mixture alternating with the intermittent reactions of the water-reactive fuel, whereby pistons of water are driven out the exhaust opening.

7. The method of operating through water a jet propulsion device comprising a duct having an inlet opening through which water enters the duct and an exhaust opening through which Water leaves the duct, and a reaction chamber within the duct opening into the duct, said method comprising intermittently introducing a waterreactive material into the reaction chamber, and intermittently introducing into the reaction chamber a carbureted mixture, the injections of the water-reactive material alternating with the injections of the carbureted mixture, and precompressing the injections of the carbureted mixture by pressure from the reactions of the water-reactive material and igniting the compressed carbureted mixtures, whereby pistons of water are driven out the exhaust opening.

8. The method of operating through water a jet propulsion device comprising a duct having an inlet opening through which water enters, an exhaust opening through which water leaves, and a reaction chamber within the duct, said method comprising the steps of injecting a waterreactive fuel into the water within said reaction-combustion chamber thereby generating gas under pressure; introducing a carbureted mixture of fuel and air into said reaction-combustion chamber, compressing said carbureted mixture by said compressed gas; igniting the carbureted mixture within the reaction-combustion chamber while under pressure; expelling the water and products of reaction and combustion at high velocity from said reactioncombustion chamber into the water in said duct thereby periodically expelling water through said exhaust opening of said duet; drawing in a new mass of water through said inlet opening and introducing a new charge of water in said reaction combustion chamber; automatically drawing in a new charge of carbureted fuel and air into said reaction-combustion chamber; introducing a new charge of water-reactive fuel into the water in said reaction combustion chamber, and repeating said steps.

9. The method of operating through water a jet propulsion device comprising a duct having an inlet opening through which water enters, an exhaust opening through which water leaves, and a reaction chamber within the duct, said method comprising the steps of injecting a water-reactive fuel into said reaction-combustion chamber thereby generating heat and gases under pressure; introducing a carbureted mixture of fuel and air into said reaction-combustion chamber at a timed interval after the injection of said water-reactive fuel; then compressing and igniting the carbureted mixture by said gases; expelling the water and products of reaction and combustion at high velocity from said reaction-combustion chamber into the water in said duct, thereby periodically expelling water through said exhaust opening of said duct; drawing in a new mass of water through said inlet opening and introducing a new charge of water in said reaction-combustion chamber; automatically drawing in a new charge of carbureted fuel and air into said reactioncombustion chamber; introducing a new charge of waterreactive fuel into the water in said reaction-combustion chamber, and repeating said steps.

10. The method of operating through water a jet propulsion device comprising a duct having an inlet opening through which water enters, an exhaust opening through which water leaves, and a reaction chamber within the duct, said method comprising the steps of: injecting into the water within said reaction-combustion chamber a water-reactive fuel and thereby generating combustible gases; introducing an excess of air into said reactioncombustion chamber in addition to said combustible gases; then injecting another charge of water-reactive fuel irlto said reaction-combustion chamber thereby generating heat and additional combustible gases under compression, blending the additional combustible gases with the mixture of air and first-mentioned combustible gases, and thereby igniting said blended gases and air within said reactioncombustion chamber; expelling the water and products of reaction and combustion at high velocity from said reaction-combustion chamber into the Water in said duct thereby periodically expelling water through said exhaust opening; drawing in a new mass of water through said inlet opening; introducing a new charge of water in said reaction-combustion chamber; automatically drawing in a new charge of air into said reaction-combustion chamber; introducing a new charge of water-reactive fuel into the water in said reaction-combustion chamber, and repeating said steps.

References Cited in the file of this patent UNITED STATES PATENTS 2,461,797 Zwicky Feb. 15, 1949 2,522,945 Gongwer Sept. 19, 1950 

4. A JET PROPULSION DEVICE ADAPTED FOR OPERATION THROUGH WATER COMPRISING: A DUCT HAVING AN INLET OPENING AND AN EXHAUST OPENING, AN AUTOMATIC PRESSURE-OPERABLE INLET VALVE LOCATED WITHIN THE DUCT FOR INTERMITTENTLY BLOCKING THE PASSAGE OF WATER ENTERING THE DUCT FROM SAID INLET OPENING, MEANS PROVIDING A REACTION-COMBUSTION CHAMBER WITHIN SAID DUCT, SAID REACTION-COMBUSTION CHAMBER BEING PROVIDED WITH AN INLET OPENING AND HAVING AN OUTLET LOCATED WITHIN THE DUCT DOWNSTREAM FROM SAID AUTOMATIC PRESSURE-OPERABLE VALVE, THE REAR END OF THE REACTION-COMBUSTION CHAMBER BEING PROVIDED WITH A DIRECTIONAL BARRIER EXTENDING SUBSTANTIALLY ACROSS THE AREA DESCRIBED BY SAID EXHAUST OPENING OF THE REACTION-COMBUSTION CHAMBER, A FUEL-MIXING CARBURETOR HAVING AN OUTLET CONDUIT LEADING INTO SAID REACTION-COMBUSTION CHAMBER FOR ADMITTING CARBURETED MIXTURE THEREIN, AN AUTOMATIC PRESSURE-OPERABLE CARBURETOR OUTLET VALVE LOCATED AT SAID OUTLET CONDUIT BETWEEN SAID CARBURETOR AND SAID REACTIONCOMBUSTION CHAMBER, A CONDUIT FOR INTRODUCING WATERREACTIVE MATERIAL INTO SAID REACTION-COMBUSTION CHAMBER INTERMITTENTLY AND THEREBY CAUSING A REACTION BETWEEN SAID WATER-REACTIVE FUEL AND WATER WITHIN SAID REACTIONCOMBUSTION CHAMBER, THEREBY ELEVATING THE PRESSURE WITHIN SAID REACTION-COMBUSTION CHAMBER, FIRING MEANS TIMED TO EXPLODE SAID CARBURETED MIXTURE ADMITTED INTO THE REACTION-COMBUSTION CHAMBER THROUGH SAID CONDUIT, WHEREBY PISTONS OF WATER ARE DRIVEN INTERMITTENTLY DOWNSTREAM THROUGH SAID DUCT EXHAUST OPENING. 